Relay having poles of independent sensitivity



fim w o m/ I I RELAY HAVING POLES OF INDEPENDENT SENSITIVITY Filed D60. 28, 1964 F. L. MALMBORG 2 Sheets-Sheet 1 44 Ali I UN i r Wl A we L/mw 6K x 3 E Q 2 m m 1 F m Dec. 13, 1966 Ex r 4 FIG. 6

RELAY HAVING POLES OF INDEPENDENT SENSITIV-ITY Filed D80. 28, 1964 Dec. 13, 1966 F. L. MALMBORG 2 Sheets-Sheet 2 mdE w mm. 8 Q in mm we h V cm mm. 8 W N m: 3 mm mm m ow vm o 9 N: E NN v:

v QE

mm 2. mm 9 g wm United States Patent 3,292,120 RELAY HAVING POLES OF INDEPENDENT SENSITIVITY Floyd L. Malmborg, Wayne, N.J., assignor to American District Telegraph Company, Jersey Qity, N..l., a corporation. of New Jersey Filed Dec. 28, 1964, Ser. No. 421,324 7 Claims. (Cl. 335-119) The present invention relates to sensitive electromagnetic relays of the multiple pole switch type and more particularly to means whereby the switch poles of such relays may be rendered operationally independent of each other. The term sensitive is employed to designate a relay which is responsive to small variations in current or voltage.

Double switch poles have long been used in relays as a means of providing additional switching elements within a single, compact unit. When a single coil and armature are employed as the motor mechanism it is obvious that both poles must possess identical operational characteristics, i.e., both pole elements will operate simultaneously upon a certain increase of applied coil potential and will release simultaneously at some lesser potential. It has been found, however, that a more compact design and hence a more efficient use of available space may be achieved by employing double coils in the relay. In such designs, the coil is divided into two separate windings, each having its own core piece, and the windings are usually wired in series connection although parallel connection is sometimes used. To complete the flux path through both core pieces and the heel piece, it is necessary to employ an armature of unitary construction and thus the switching poles must operate in conjunction as was the case when a single coil Was used.

Interpedence of the switching poles prevents the use of different pick-up and release current values for each pole and thus severely limits the application of the relay in circuit design. The present invention, through the provision of an additional flux path and individual armatures, establishes independent motor mechanisms for each switching pole thereby permitting each pole to possess individual operational characteristics. The flexibility thus gained is of great value to the circuit designer for a relay so constructed is really three relays combined in a single unit since, through external circuitry, each side may be used independently in separate circuits or the two coils may be wired in series or parallel within the same circuit. Moreover, the current values for the pick-up and release of each pole may be adjusted without disturbing the adjustment of the other pole.

It is important that a sensitive relay require a minimum amount of power for its operation and, to be commercally feasible, the relay must be simple and economical to manufacture and assemble, The design must also be compact, reliable in service and provide isolation of the potentials to be switched from the operating potentials to avoid service troubles arising from electrical leakage and short circuits.

Accordingly, an object of the present invention has been the provision of a sensitive, multiple switch pole relay capable of performing mutually independent switching operations.

A further object has been the provision of a relay which, by means of external circuitry, may perform the functions of several relays.

Another objective has been the provision of a multiple switch pole relay in which the operational characteristics of each switch pole may be varied independently of the other switch pole.

Still another object has been the provision of a multiple switch pole relay of compact design requiring a small amount of power for operation.

A feature of the invention is that the potentials to be switched are electrically isolated from the potentials applied to the coils.

Another feature of the invention is the means provided to facilitate the proper alignment of the armatures with the faces of the magnetic pole piece during assembly, thus afiording simple and economical manufacture.

Other and further objects, features and advantages of the invention will appear more fully from the following description of an embodiment of the invention taken in connection with the appended drawings, in which:

FIG. 1 is an exploded isometric view of a double pole relay utilizing the features of this invention;

FIG. 2 is a schematic view of the motor mechanisms of a double pole relay utilizing the features of this in vention and indicating one arrangement of flux paths which are possible therewith;

FIG. 3 is a side elevational view of a coil assembly useful in the practice of this invention;

FIG. 4 is a front elevational view of a double pole relay utilizing the features of this invention, shown in the operated condition with the cover cut away for ease of understanding;

FIG. 5 is a sectional view taken generally along line 5-5 of FIG. 4 and showing the relative position of coil, armature and contacts of a relay utilizing the features of this invention when in the released condition; and

FIG. 6 is a schematic view of the motor mechanisms of a multiple pole relay utilizing the features of this invention.

For illustrative purposes, the drawings show a double throw contact arrangement. It will however be apparent to those skilled in the art that other contact arrangements may readily be provided.

As best seen in FIGS. 1, 4 and 5, the relay 10 of this invention comprises coil assemblies, armatures and contacts. The coil assembly and all the other components are supported on a bracket 12 made of non-magnetic material, such as brass. The lower end of the bracket 12 is bent to provide a foot 14 secured to the metal base 16 by two of the four rivets indicated at 118 which secure to the base 16 a conventional multi-prong plug 20 having prongs 22. Solder terminals or leads may be alternately supplied for the electrical connection of the relay to a circuit.

The basic coil assembly 24 (FIGS. 2 and 3) has a frame 26 connected to bracket 12 by machine screws 28 engaging tapped holes 30. The frame 26 is made of nonmagnetic material, such as sheet brass, and is formed into substantially a U-shape by bending arms 32, 34 into parallel relationship. The arms 32, 34 are drilled in axial alignment to receive three magnetic circuit elements 36, 38, 40 in substantially parallel and planar alignment, the latter members are manufactured of a non-retentive magnetic material, such as an electrical steel, for example, Allegheny-Ludlum Company alloy #4750. The circuit elements 36, 38, 40 are provided with washer shaped pole pieces 42, 44, 46, also formed of non-retentive magnetic material, which are pressed onto the elements 36, 38, 40 and finished flush with the upper end surface thereof. A heel piece 48, also made of non-retentive magnetic material, is provided with three holes 50, 52, 54 to receive the other ends of the elements 36, 38, 40. Two electromagnetic coils 56, 58 consist of a predetermined number of turns of insulated wire of a predetermined size wound on a hollow spool 60 and provided with terminals 62 connected by conductors 64 to prongs 22. A coil assembly may be made by placing the two coils 56, 58 and associated spring washers 66 in position between the frame arms 32 and 34, and pressing the elements 36, 38, 40 into the heel piece 48 until the inner surfaces of the three pole pieces 42, 44, 46 contact the frame arm 32. The elements 36, 40 pass through the hollow center of the coils 56, 58, respectively, and act as cores for the coils. The spring washers 66 serve to hold the heads of the spools 60 firmly against the underside of frame arm 32.

In FIG. 2, the windings of the coils 56, 58 are shown schematically and two armatures 68, 70 are shown to better illustrate the magnetic circuits, or flux paths, indicated by the arrows. A distinct, individual magnetic circuit is provided for each coil 56 or 58 extending from each coil core 36 or 40 through the associated armature 68 or 70, the common central magnetic member 38, the heel piece 48, and back to the individual coil cores. It will be evident that electrical polarity must be observed when the coils are wired into a circuit.

As shown in FIGS. 4 and 5, an armature support assembly comprises two parallel flanges 72 extending back from the outer sides of the upper end of the bracket 12, in substantailly parallel alignment, and a third substantially parallel flange 74 extending from the center of the bracket 12, to form bearing supports for the armatures. The center flange 74 is provided with a double ended pivot bearing 76. The flanges 72 are drilled, tapped and split in the conventional manner, as at 78, to receive two threaded members 80 whose inboard ends are provided with pivot bearings. Two plates 82, constructed of an insulating material, are fastened, for instance by rivets 84, to the flanges 72. Two L-shaped, electrically conductive brackets 86 are fastened, one above the other, to the inboard side of each plate 82, for instance by eyelets 88. The inboard ends of brackets 86 are drilled, tapped and split in the conventional manner to receive four electrical ly conductive screws 90, 92, 94, 96 made, for instance, of brass tipped with a special contact material such as palladium or gold. The screws 90, 92, 94, 96 constitute the fixed switching contacts of the relay. Electrical connection to each of the four brackets 86 is achieved by electrically bonding conductors 98 to the brackets 86 by means of the eyelets 88, or equivalent means, the other ends of the conductors 98 being electrically bonded each to one of the prongs 22 of plug 20.

Also connected to the inboard side of plates 82 are two electrically conductive, resilient elements 100, which may be formed from thin gage phosphor bronze material, each having an arm 102 extending toward the center of the relay. Each of the arms 102 is provided with a notch 104 into which is soldered one end of a biasing means 105, 106, such as a coil spring. Conductors 108 are electrically bonded to the elements 100, for instance through the eyelets 110, and to prongs 22 in plug 20.

The two armatures 68 and 70 are each formed of a substantially Z-shaped plate 112 of non-retentive magnetic material, such as an electrical alloy steel. Pivot pins 114 are connected transversely to the crossbar 116 of the Z- shaped armatures to support the armatures 68 and 70 between the threaded members 80 and the double ended pivot bearing 76. The entire armature assemblies are so designed and proportioned as to be substantially in balance around the pivot pins 114. Each armature pivots in response to energizing current flow in the respective coils to magnetically interconnect the corresponding core to the adjacent magnetic circuit element. Adjustment of the threaded members 80 provides the proper amount of bearing clearance to allow free rotation of the armatures. An insulating block 118 is connected, for instance by a rivet 119, to the end portion 120 of the armature. Each block 118 is provided with a conducting member 121, 122 having electrical contacts, such as palladium or gold, which provide a conductive medium extending through the blocks 118 to form contacts 123, 124 and 125, 126 on each side thereof. The contacts 123 and 124 are provided with solder terminals 128 to which are soldered the other ends of the biasing means 105, 106. Electrical connection is thus established between the conducting members 121, 122 and respective prongs 22 in the plug 20.

Contacts 125, 126 are moved into contact with switching contacts 94, 96, respectively when armatures 68, 70 pivot in response to energizing current flow in the coils 56, 58, respectively. Adjusting screws 130 are provided in tapped holes 131 in the insulating plates 82 and arranged to bear against the resilient elements 100 in such manner that advancement or retraction of the screws 130 will displace the associated arm 102 thereby varying the tension in the biasing means 105, 106 and consequently varying the pressure existing between the contacts 123, 124 and the lower pair of screws 90, 92, respectively, when the coils are deenergized. The adjustment of the contact pressure at each pole is independent of adjustment of the contact pressure at the other pole, and because the armatures are balanced, the contact pressure is dependent solely upon the adjustment of biasing means 105, 106, thereby allowing the maximum: degree of freedom in the setting of the desired contact pressure. A thin sheet of insulating material 132 is provided between the bracket 12 and the biasing means to prevent possible short circuits between electrically alive parts.

As shown in FIGS. 4 and 5, the conducting members 121, 122 are in substantial axial alignment with each pair of fixed contacts or screws 94 and 92, 96, respectively. Cont-acting surface 123 is yieldably urged into contact with fixed contact 90 by biasing means 105. Similarly, contacting surface 124 is yieldably urged into contact with fixed contact 92 by biasing means 106. The insulating blocks 118 prevent the potentials being switched through the contacts from being transferred to the bracket 12 and so afford a great degree of isolation from the operating potentials applied to the coils 56, 58. Such isolation is an important factor in avoiding service troubles arising from electrical leakage and short circuits.

After the armatures and contact supporting units have been mounted on bracket 12, the coil unit assembly is installed by means of the screws 28 which pass through elongated slots 134 and engage tapped holes 30 in the frame 26. The elongated slots 134 permit rapid and easy positioning of the coil unit assembly so that the pole pieces 42, 44, 46 are in proper alignment and spacing with the armatures 68, 70. The position of the pole pieces is, in effect, adjustable with respect to the pivot points of the armatures. The adju-stability of the coil assembly position is an extremely important feature in the manufacture of the relay, because experience with other designs has shown that the cost of adjusting a relay at assembly may well exceed the cost of the manufacture and assembly of all the parts. Finally, a metal case 136 fitted with an insulating liner 138 is fastened to the base 16 by means of three screws 139. Y

The performance of a double pole, double throw relay constructed in accordance with the principles of the invention is demonstrated by the following data which has been extracted from measurements made under normal operating conditions. The coils of the relay under test were each wound with 5490 turns of number 36 enamel insulated wire to produce a measured coil resistance of about 210 ohms each. The residual gap (between armatures and pole pieces) was adjusted to .0025 inch, the gap at the normally open contacts were adjusted to .004 inch and the pressure at the normally closed contacts adujsted to grams. Separate circuits including a source of potential, a potentiometer and a milli-ammeter were provided for each coil and a third circuit with a source of potential and pilot lamps to afford distinct indication of the moment of transfer of the contacts was connected to the relay poles. Under the above conditions, the relay oper ated at the following current values:

Pick-Up, ma. Release, ma.

Coil No. 1 4.05 2.0 Coil N0. 2 4.0 2.0 Coil No. 1 (Co 3.95 1. 90 Coil 2 (Coil 1 energized) 3. 78 1.80 Coils No. 1 and 2 in series 4. 05 2.00

When the residual gap of both armatures was increased to .006 inch, the following results were obtained:

Pick-Up, ma. Release, ma.

Coil No. 1 5. 35 3. 62 Coil No. 2 5.1 3. 33 Coil No. 1 (Coil 2 energized). 4. 90 3. 35 Coil No. 2 (Coil 1 energized) 4. 85 3.05 Coils No. l and 2 in series a. 5. 35 3. 33

When the residual gap increased to .010 inch:

Pick-Up, ma. Release, ma.

Coil No. 1 6.15 5.05 Coil No. 2 6. 2 5.0 Coil No. 1 (Coil 2 energize 5. 7 4.6 Coil No. 2 (Coil 1 energized) 5. 85 4. 6 Coils No. 1 and 2 in series 6. 2 5. 0

and is found to be 3.36 milliwatts to reach coil individually or 6.72 milliwatts taken together. Thus the relay is conservatively rated as operable at five miliwatts per pole. Operation with the coils connected in parallel produces similar reults because the response depends entirely on the current flowing through the individual coils rather than the external circuit arrangements.

The maximum power that may be continuously applied to the relay depends upon the temperature rise and is 4 watts based upon the 100' C. rating of the Class A insulation employed. Higher power, however, may be applied for brief intervals.

The principle of the invention may be applied in modified form to relays having more than two switch poles. FIG. 6 is a schematic illustration of a multiple pole relay 140 which has a multiplicity of motor mechanisms and its operation may be understood in consideration of the foregoing description of a double pole relay.

A plurality of cores 14 2, 144, 1 46 are mounted in a heel piece 148. A plurality of non-retentive magnetic members 150, 152 are also mounted in the heel piece 148 disposed between the cores 142, 144, 146. Electromagnetic coils 154, 156, 158 are mounted about cores 142, 144, 146, respectively. Pole pieces 160, 162, 164, 166, 168 are provided on each of the cores 142, 144, 146 and the magnetic members 150, 152 at the end opposite the heel piece 148. A plurality of armatures 170, 172, 174, 176 are provided. The armature 170 is arranged to pivotally contact the pole pieces and 162. The armature 172 is arranged to pivotally contact the pole pieces 162 and 164. The armature 174 is arranged to pivotally contact the pole pieces 164 and 166, and armature 176 is arranged to pivotally contact the pole pieces 166 and 168.

In this design armature 170 is operated by the ene-rgization of coil 154, armature 176 by coil 158, and armatures 172 and 174 respond to coil 156. Thus, while armatures 170 and 176 are independent of each other and armatures 172 and 174, armatures 172 and 174 must operate together except for such differences as can be established through individual adjustment of the contact gaps and pressures. It will be evident that still further switch poles may be provided through the addition of other pairs of core units and coils, each such combination providing another switch pole. However, the limitation exists that adjacent armatures will be linked together as described above but each such pair will be independent of other pairs and of the single armature at each end of the assemblage.

While the invention has been described in connection with specific embodiments thereof and in connection with specific uses, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. An electromagnetic relay, comprising:

(a) a plurality of parallel magnetic core members;

(b) an individual energizing coil disposed about each of said core members, said coil being responsive to an external source of signals;

(c) a non-retentive magnetic circuit element disposed between each pair of said core members;

(d) an individual armature element for each of said core members;

(e) means pivot-ally mounting said armature elements so that said armature elements each move to a position magnetically interconnecting the corresponding core and an adjacent magnetic circuit element in response to energizing current flow in the corresponding one of said coils;

(f) biasing means urging said armature out of said position thereof;

( g) magnetic circuit means intercoupling said respective cores and adjacent magnetic circuit elements to provide, with said respective armatures, an individual magnetic circuit for each of said cores; and

(h) electrical switching contacts operatively coupled to said armatures for operation by said armatures upon pivoting motion of the latter.

, 2. A relay comprising:

(a) first and second electromagnetic coils, each of said coils being responsive to an external source of signals;

(b) a magnetic core disposed within each of said coils;

(c) a non-retentive magnetic circuit element disposed between said cores;

(d) a heel piece connecting said cores and magnetic circuit elements;

(e) first and second armatures each having first and second end portions and being associated with said first and second coils, respectively;

(f) means for pivotally mounting said first armature such that said first end portion magnetically interconnects said first coil and said magnetic circuit element in response to energizing current flow in said first coil;

(g) means for pivotally mounting said second armature such that said first end portion magnetically interconnects said second coil and said magnetic circuit element in response to energizing current flow in said second coil;

(h) biasing means urging said armatures out of said magnetically interconnected positions;

(i) first and second switching contacts associated with each of said armatures;

(j) an armature contact element insulatingly mounted in said second end portion of each of said armatures and adapted to be in electrical contact with said first switching contact when said associated coil is energized, and with said second switching contact when said associated coil is not energized.

3. An electromagnetic relay of the multiple pole switch type which is responsive to small variations in current or voltage comprising:

(a) a support base;

(b) a non-magnetic bracket connected to said base;

(c) a coil assembly further comprising:

(1) a frame of non-magnetic material connecting said coil unit assembly to said non-magnetic bracket,

(2) at least three non-retentive magnetic circuit elements supported from said frame and disposed in spaced apart and parallel relationship to each other,

(3) a heel piece of non-retentive magnetic material connecting one end of each of said magnetic circuit elements to the respective ends of the other of said magnetic circuit elements,

(4) a plurality of pole pieces, each connected to the end of one of said magnetic circuit elements opposite said heel piece,

(5) a plurality of electromagnetic coils disposed each about a successive alternate magnetic circuit element,

(d) an armature support means comprising a plurality of flanges connected to said non-magnetic bracket;

(e) a plurality of armature assemblies further comprising:

( 1) a non-retentive magnetic plate,

(2) an insulating member fixedly connected to one end of each of said plates;

(3) a pivot pin connected to said plate so that said armature assemblies are substantially in balance around said pivot pins, said pivot pins being adapted to pivotally engage said armature support flanges;

(4) an electrical conducting member extending through said insulating member to form first and second contacts on opposite sides thereof, said armature assemblies being mounted one between each adjacent pair of said support means flanges, such that said metal plate of said armature assembly may reciprocally pivot to magnetically interconnect said pole pieces of two adjacent magnetic circuit elements in response to energizing current flow in the coil associated with one of said elements,

(f) a plurality of electrically conducting biasing elements urging said armatures out of said magnetically interconnecting position;

(g) a plurality of first and second electrical switching contacts each insulatingly supported from said nonmagnetic bracket;

(1) each of said first switching contacts being disposed in spaced relation to one of said first contacts of said armature assemblies,

(2) each of said second switching contacts being disposed in spaced relation to one of said second contacts ofsaid armature assemblies,

(3) each of said biasing elements resiliently urging one of said first armature contacts into contact with one of said first switching contacts and away from said second switching contact,

(4) each of said armature assemblies individually pivoting and urging one of said second armature contacts into contact with one of said second switching contacts in response to energizing current flow in an associated coil.

4. A relay as defined in claim 3, comprising means to adjust the amount of bias imparted by each of said biasing elements.

5. A relay as defined in claim 3 further comprising means to align said coil assembly and armature assemblies by adjusting the position of said pole pieces relative to the pivot points of said armatures.

6. An electromagnetic relay of the double pole switch type which is responsive to small variations in current or voltage comprising:

(a) a support base;

(b) a non-magnetic bracket connected to said base;

(c) an electromagnetic coil assembly further compris- (1) a frame of non-magnetic material connected to said non-magnetic bracket,

(2) first, sec-ond and third non-retentivemagnetic circuit elements disposed in spaced apart and parallel planar relationship to each other and supported by said frame,

(3) a heel piece of non-retentive magnetic material connecting one end of each of said mag netic circuit elements to the corresponding end of the other of said magnetic circuit elements,

(4) first, second and third pole pieces, respectively connected to the end of each of said first, second and third magnetic circuit elements opposite said heel piece,

(5) first and second electromagnetic coils disposed one about each of said first and third non-retentive magnetic circuit elements which are farthest removed from each other,

(d) an armature support comprising first, second and third flanges connected to said non-magnetic bracket and extending from said bracket in a direction opposite from said coil assembly, said flanges being disposed in parallel array to each other;

(e) first and second armature assembles, each comprising:

(1) a non-retentive magnetic plate,

(2) an insulating member fixedly connected to one end of said plate,

(3) an electrically conducting member extending through said insulating member to form first and second contacts on opposite sides thereof,

(4) a pivot pin connected to said plate so that said armature assemblies are substantially in balance around said pivot pins, said first armature assembly being mounted between said first and second flanges, such that the end of said plate opposite said insulating member may reciprocally pivot to magnetically interconnect said first and second pole pieces in response to energizing current flow in said first coil, said second armature assembly being mounted between said secand and third flanges, such that the end of said plate opposite said insulating member may reciprocally pivot to magnetically interconnect said second and third pole pieces in response to energizing current flow in said second coil,

(f) biasing means comprising first and second coil springs urging said first and second armature plates out of said magnetically interconnecting position;

(g) an electrical switching contact assembly comprising first, second, third and fourth electrical switching contacts supported by and insulated from said non,- magnetic bracket;

9 10 (1) said first and second switching contacts being 7. A relay as defined in claim 6 further comprising disposed in paced l ti h t id fi t means to adjust each of said switching contacts with relatacts of Said first and second armature assem; tion to a respective one of said first and second armature contacts. b ies, respectively, whereby each 1s removably 5 References Clted by the Examiner contactable by said first contact, (2) said third and fourth switching contacts being UNITED STATES PATENTS disposed in spaced relation each t said second 2,930,889 3/1960 Hours 200-87 contacts of sa1d first and second armature as BERNARD A GILHEANY Primary Examiner sembhes, respectively, whereby each is remov- 10 ably contactable by said second contact. ENVALL: Assistant Examiner- 

1. AN ELECTROMAGNETIC RELAY, COMPRISING: (A) A PLURALITY OF PARALLEL MAGNETIC CORE MEMBERS; (B) AN INDIVIDUAL ENERGIZING COIL DISPOSED ABOUT EACH OF SAID CORE MEMBERS, SAID COIL BEING RESPONSIVE TO AN EXTERNAL SOURCE OF SIGNALS; (C) A NON-RETENTIVE MAGNETIC CIRCUIT ELEMENT DISPOSED BETWEEN EACH PAIR OF SAID CORE MEMBERS; (D) AN INDIVIDUAL ARMATURE ELEMENT FOR EACH OF SAID CORE MEMBERS; (E) MEANS PIVOTALLY MOUNTING SAID ARMATURE ELEMENTS SO THAT SAID ARMATURE ELEMENTS EACH MOVE TO A POSITION MAGNETICALLY INTERCONNECTING THE CORRESPONDING CORE AND AN ADJACENT MAGNETIC CIRCUIT ELEMENT IN RESPONSE TO ENERGIZING CURRENT FLOW IN THE CORRESPONDING ONE OF SAID COILS; (F) BIASING MEANS URGING SAID ARMATURE OUT OF SAID POSITION THEREOF; (G) MAGNETIC CIRCUIT MEANS INTERCOUPLING SAID RESPECTIVE CORES AND ADJACENT MAGNETIC CIRCUIT ELEMENTS TO PROVIDE, WITH SAID RESPECTIVE ARMATURES, AN INDIVIDUAL MAGNETIC CIRCUIT FOR EACH OF SAID CORES; AND (H) ELECTRIC SWITCHING CONTACTS OPERATIVELY COUPLED TO SAID ARMATURES FOR OPERATION BY SAID ARMATURES UPON PIVOTING MOTION OF THE LATTER. 